A network device needs a network address, such as an IP (Internet Protocol) address, in order to effect communication on a network. The network address allows the device to uniquely identify itself on the network, and enables other devices on the network to direct messages to that network address, and hence, that device.
In many networks, the number of devices or nodes is greater than the number of network addresses available to the network. Because there are more nodes than network addresses, it is not possible to permanently assign a unique network address to each and every node. In such networks, network communication is enabled by having the various devices share the available network addresses. Sharing is made possible by the fact that many network devices do not need to be connected to the network all of the time. For example, a company may have many portable computers that are connected to the network only during certain times, and at all other times are completely disconnected from the network. Because many network devices need to connect to the network only some of the time, it is possible for those devices to share network addresses.
To enable the sharing of network addresses, a network address assignment server is usually implemented. This server, often referred to as a DHCP (dynamic host configuration protocol) server, is responsible for the assignment and reclamation of network addresses. More specifically, when a network device (e.g. a portable computer) needs to communicate on the network, the device submits an address request to the DHCP server. The DHCP server responds to this request by dynamically assigning a network address to the device. The device thereafter uses the network address to effect communication on the network, and as long as the device is connected to the network, that network address belongs to that device. At some point, the device logs off from the network. When that happens, the DHCP server reclaims the network address, and is thereafter free to assign the network address to some other network device. The network address is thus shared among multiple devices.
Typically, the operation of the DHCP server is dictated by a set of configuration information. The configuration information may specify, for example, which network addresses can be assigned by the DHCP server. The DCHP server uses the configuration information to determine its behavior during runtime. Typically, the configuration information takes the form of a text file that is read by the DHCP server when the server starts up.
At certain times during the operation of the DHCP server, it may be necessary to update the configuration information. Currently, to update the configuration information, some mechanism other than the DHCP server is used. For example, an administrator may use a text editor to edit the text file in which the configuration information is stored. Once the text file is updated, the DHCP server is restarted to cause the DHCP server to read the updated text file and to implement the updated configuration information contained therein. Thus, in the current implementation, updating the configuration information and having the DHCP server implement the update requires the server to be shut down and restarted, which in turn requires server downtime.